US5197968A - Disposable tissue retrieval assembly - Google Patents

Abstract

The present invention provides an apparatus for retrieval, dissection and removal of small organs and tissue from a patient's body. The instrument includes a collapsible basket defining a basket cavity. An anvil is attached to the distal end of the basket to form an impacting surface. A cutting cannula defining a cutting cavity is positioned to be reciprocatingly movable to pass through the basket cavity and impact the anvil. The cutting cannula is manually and reciprocatingly driven to pass into and through the basket cavity, cutting any tissue contained in the basket cavity. The cut tissue is then suctioned from the body for analysis.

Description

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to a tissue retrieval assembly for holding and dissecting bodily tissue. More particularly, the present invention relates to a disposable instrument useful for laparoscopic procedures. The disposable instrument has a basket for holding tissue and a cutting element for dissecting held tissue. Tissue samples out away by the disposable instrument can be optionally held in a tissue trap container.

Laparoscopic surgery can be effectively used for removal of gall bladders, ovaries, tumors, or other body organs or tissues found in the abdominal cavity. Commonly, a cutting instrument attached to an end of a cannula is used to excise tissue. The excised tissue is then immediately sucked up through the cannula for disposal as medical waste. Alternatively, excised tissue can be grasped or held by tweezers, pincers, or other similar medical devices, and pulled out through a cannula inserted into an abdominal cavity through a laparoscopic puncture.

However, medical devices constructed for the practice of the foregoing tissue retrieval methods are not always suitable for retrieving relatively large bits of tissue, and/or small organs. Excised bits of tissue can be lost or move away from the operating site before they are sucked, grasped or pulled through a cannula. In addition, larger bits of tissue and small organs will not fit in one piece through the small diameter cannula used in laparoscopic procedures. Since the cannula diameter should be minimized to reduce patient trauma, simply providing larger cannula is not desirable.

The present invention provides an apparatus for retrieval of small organs and tissue from a patient's body. Tissue is dissected and removed from a patient with the aid of an instrument that includes a collapsible basket formed to define a basket cavity to contain tissue. Optionally, an anvil is attached to the basket to form an impacting surface. The basket can be collapsed to allow insertion of the collapsible basket into, and withdrawal from, a patient's body.

A cutting cannula, formed to define a cutting cannula cavity, is positioned to be reciprocatingly movable to pass through the basket cavity and impact the anvil. In operation, the cutting cannula is manually and reciprocatingly driven to pass into and through the basket cavity, cutting any tissue contained in the basket cavity. The cut tissue is then withdrawn from the patient and saved for analysis or disposed of as medical waste.

In preferred embodiments, the collapsible basket includes a plurality of flexible members. Each flexible member has a first and a second end and is prestressed to define an arcuate shape between its first and second ends. The first end of each flexible member is attached to a support tube positioned to surround the cutting cannula, and the second end of each flexible member is attached to the anvil. With this attachment arrangement the anvil is supported and the basket cavity is defined between the support tube and the anvil.

In preferred embodiments, a shield tube is positioned to surround the support tube, and the shield is movable forward over the basket to straighten and effectively collapse the flexible members forming the basket. Withdrawal of the shield tube from contact with the flexible members allows recovery of their arcuate shape and reformation of the basket cavity.

In another preferred embodiment, the cutting cannula is reciprocatingly moved with the aid of a support tube attached to hold the basket, a handle attached to the support arm, and a lever arm attached to the cutting cannula. The lever arm is biasingly connected to the handle (typically by a hinge/spring system) so that operational movement of the lever arm relative to the handle moves the cutting cannula toward the anvil. A biasing element, such as a spring, is connected to move the lever arm away from the handle to encourage reciprocating motion of the cutting cannula. The cavity of the cutting cannula is attached in fluid connection to a vacuum source.

The present invention also encompasses a method for dissecting and removing tissue from a patient's body. The method includes the steps of entrapping tissue in a collapsible basket formed to define a basket cavity, providing an anvil attached to the basket, and cutting tissue trapped in the basket by reciprocating motion of a cutting cannula, the cutting cannula being movable to pass through the basket cavity and impact the anvil, cutting any tissue contained in the basket cavity. Any cut tissue is contained in the cutting cannula cavity is withdrawn for analysis or disposal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a tissue retrieval assembly that includes a disposable instrument connected to a vacuum source. A tissue sample trap for retention of tissue extracted with the aid of the disposable instrument is shown;

FIG. 2 illustrates a working end, normally inserted into a patient's abdomen, of the disposable instrument as shown in FIG. 1. A basket attached to a support tube at one end is shown collapsed by movable shield tube concentrically disposed to fit over the support tube and the basket;

FIG. 3 illustrates the basket, fully expanded after withdrawal of the shield tube, with each prestressed flexible strip composing the basket being attached to the support tube and to an anvil;

FIG. 4 shows the shield tube moving forward to partially collapse the basket and closely entrap and hold a tissue sample;

FIG. 5 shows a cutting cannula reciprocally positioned in the support tube, with the cutting cannula extending out from the working end of the support tube to pass through the basket and impact the anvil, cutting a core out of the tissue contained in the basket;

FIG. 6 shows the cutting cannula retracted and the shield tube moved forward to compress the basket and to firmly hold the tissue sample; and

FIG. 7 illustrates an anvil having no central plug to allow a conformably dimensioned cutting cannula to slide into an anvil cavity, cutting away any contained tissue sample.

DETAILED DESCRIPTION OF THE INVENTION

As illustrated in FIG. 1, atissue retrieval assembly 10 includes adisposable instrument 12 in fluid connection with a tissuesample trap system 100 andvacuum source 105. Thedisposable instrument 12 includes asupport tube 14, with thesupport tube 14 having a workingend 17 that is inserted into a patient's body for dissection and removal of the tissue. Thesupport tube 14 internally defines asupport tube cavity 16 and externally definesthreads 18. Preferably, the support tube is 14 is constructed from tubular surgical steel, aluminum, or other rigid, biocompatible metal. Alternatively, substantially rigid thermoset plastics such as polyethylene, polypropylene, or polycarbonates can be used. In the embodiment illustrated, thesupport tube cavity 16 is formed to have a substantially circular cross section (taken perpendicular to the longitudinally extending tube 14), but alternative cross sections such as elliptical, rectangular, square, etc., are also contemplated. In the illustrated embodiment, thesupport tube 14 has a diameter of about 6 mm, but the diameter can typically range from about 4 mm to about 12 mm or more.

Thesupport tube 14 is connected to ahandle 20 that can be held by a surgeon or other medical personnel operating thedisposable instrument 12. Concentrically disposed within thesupport tube cavity 16 is acutting cannula 30. Thecutting cannula 30 internally defines acutting cannula cavity 32 and has a sharpenedcutting tip 31. Like thesupport tube 14, thecutting cannula 30 is typically constructed from tubular surgical steel, aluminum, or other rigid, biocompatible metal. Alternatively, substantially rigid thermoset plastics such as polyethylene, polypropylene, or polycarbonates can be used. If plastics are used to formcutting cannula 30, however, the sharpenedcutting tip 31 of thecutting cannula 30 is generally tipped with sharp edged metal to enhance its cutting efficacy. In the embodiment illustrated, thecutting cannula cavity 32 is formed to have a substantially circular cross section (taken perpendicular to the cannula 30), but alternative cross sections such as elliptical, rectangular, square, etc. can also be used. In the illustrated embodiment, thecutting cannula 30 has a diameter of about 5 mm, but the diameter can typically range from about 2 mm to about 12 mm or more, subject to the limitation that thecutting cannula 30 must fit within thesupport tube cavity 16.

Thecutting cannula 30 is concentrically disposed for reciprocal movement within thesupport tube cavity 16. Thecutting cannula 30 is attached to thelever arm 22. Thelever arm 22 is connected to thehandle 20 by ahinge 26 and aspring 24. Thespring 24 is formed from a single piece of strip steel that is bent and positioned between thehandle 20 and thelever arm 22. The force exerted by thespring 24 acts to force apart thehandle 20 from thelever arm 22.

In operation, an operator of thedisposable instrument 12 simultaneously grasps thehandle 20 with fingers of a hand and also grasps thelever arm 22 with the thumb and palm of the hand. Bringing the thumb and fingers together with sufficient force to overcome the biased force exerted byspring 24 causes thelever arm 22 to move closer to thehandle 20. This in turn causes movement of the attached cuttingcannula 30 toward and out from the workingend 17 of thesupport tube 14. The biased force ofspring 24 is then allowed to force apart thelever arm 22 and thehandle 20 as the grip of the operator is relaxed. The cuttingcannula 30 is withdrawn into thesupport tube cavity 16 and the operator of theinstrument 12 can repeat the cycle of grip/release to drive the cuttingcannula 30 out of and into thesupport tube cavity 16.

Although imparting reciprocating movement to the cuttingcannula 30 is simple and effective with the above described lever arm mechanism, alternative embodiments having different reciprocating mechanisms are also contemplated. For example, tension or compression springs, rather than strip springs can be used to force thelever arm 22 apart from thehandle 20. In other embodiments, no biasing mechanism is used at all, with an operator directly pushing and pulling a cutting cannula. Alternatively, other mechanical drives such as screw mechanisms, pneumatic drives, vacuum drives, or electrical mechanisms can be used to drive the cutting cannula forward and backward through thesupport tube 14. In addition to manual operation, automatic and semi-automatic mechanisms that drive the cutting cannula are contemplated within the scope of this invention.

Ashield tube 40, formed to define ashield tube cavity 42, is concentrically disposed about thesupport tube 14. Theshield tube 40 is connected to a threadedadapter 44 for engaging in threaded connection thethreads 18 externally defined on thesupport tube 14. Screwing motion applied to either theshield tube 40 or the threadedadapter 44 allows an operator to move the shield tube longitudinally along thesupport tube 14 either toward the workingend 17 or away from the workingend 17, toward thehandle 20.

Like both the cuttingcannula 30 and thesupport tube 14, theshield 40 is preferably constructed from tubular surgical steel, aluminum, or other rigid, biocompatible metal. Alternatively, substantially rigid thermoset plastics such as polyethylene, polypropylene, or polycarbonates can be used to form theshield 40. In the illustrated embodiment, theshield 40 has a diameter of about 7 mm, but the diameter can typically range from about 5 mm to about 12 mm or greater, subject to the limitation that it must fit over thesupport tube 14.

As shown in FIGS. 2-6, abasket 50 composed of a plurality offlexible strips 52, is used to entrap and hold tissue in abasket cavity 51 Each of theflexible strips 52 have first ends 54 and second ends 56. The first ends 54 are attached to the workingend 17 of thesupport tube 14. The second ends 56 of theflexible strips 52 are attached to ananvil 60. Optionally, the ends 56 can be directly attached to each other (e.g. by welding attachment) to form a basket (not shown). The flexible strips are formed from surgical steel, and are prestressed to assume an arcuate, smoothly curving shape between their respective first and second ends when not constrained by theshield tube 40.

In their fully expanded position, the plurality offlexible strips 52 define a roughlyspherical basket 50 such as illustrated in FIG. 4. The flexible strips 52 can move slightly apart from each other to accommodate passage oftissue 15 from a patient into thebasket cavity 51. Movement of theshield tube 40 forward over thebasket 50 causes thebasket 50 to gradually collapse, reducing the volume of thebasket cavity 51 and straightening the flexible strips 52. A partially collapsedbasket 50 is best illustrated in FIGS. 4 through 6. Completely covering thebasket 50 with the shield 40 (as shown in FIG. 2) facilitates insertion of thebasket 50 into a patient, and retraction of theshield 40 allows capture of tissue in thebasket cavity 51.

Tissue or organs captured in the basket cavity are cut into smaller pieces by action of the cuttingcannula 30 moving forward to compresstissue 15 between itself and theanvil 60. As illustrated in FIGS. 1-6, theanvil 60 is constructed of surgical steel to define atubular cavity 62. A solid plug is inserted into thetubular cavity 62 to provide a solid impacting surface against which the cuttingcannula 30 can be contacted. Preferably, the plug is constructed from rigid polymeric material such as polyethylene and permanently force fitted into thecavity 62.

In alternative embodiments, such as illustrated in FIG. 7, thetubular cavity 62 and the cuttingcannula 30 are dimensioned to allow the cuttingcannula 30 to conformably slide into thetubular cavity 62 of theanvil 60. Asleeve 63 can be inserted into thetubular cavity 62 of theanvil 60 to allow a conforming fit with the cuttingcannula 30. In operation, the cuttingcannula 30 will forcetissue 15 into thetubular cavity 62 as it moves toward theanvil 60, and cut that tissue away from the main tissue mass as the cuttingcannula 30 moves into thecavity 62.

Tissue "cores" cut away fromtissue 15 by the slicing impact action of the cuttingcannula 30 against theanvil 60 can be removed by suction applied through the cuttingcannula cavity 32. As shown in FIG. I, the cutting cannula cavity is in fluid communication withvacuum source 105 by way of tissuesample trap system 100. The tissuesample trap system 100 allows recovery for analysis or disposal of the tissue sample core cut away by the cuttingcannula 30. As illustrated in FIG. 1, the tissuesample trap system 100 includes adual valve 110, similar to the valve described in FIG. 10 of U.S. Pat. No. 5,019,054, issued May 28, 1991 to Clement et al., the disclosure of which is herein incorporated by reference. Thesystem 100 includes avalve 110 connected to container 170 for holding tissue samples (not shown). Thevalve 110 is formed to define first andsecond passageways 126a and 126b. Thepassageways 126a and 126b are alternately operably connected in fluid communication with athird passageway 128 defined in thevalve 110. Arotor 150, formed to define twotransaxial passageways 164a and 164b, can be rotated between a first position in which passageway 164a connects in fluid communicationthird passageway 128 andfirst passageway 126a, and a second position (not illustrated) in whichpassageway 164b connects in fluid communicationthird passageway 128 andsecond passageway 126b.

Thethird passageway 128 is also in fluid connection withconduit 129.Conduit 129 is formed of a flexible plastic and terminates in anadaptor 120 for mating connection with surgical instruments, lavages, cannulas, or other devices for retrieving bodily fluids and tissues. In alternative embodiments, thevalve 110 can be fitted with an integral conduit piece (not shown) to aid in retrieval of fluid and tissue samples from a patient.

Thefirst passageway 126a is connected through conduit 132a, T-conduit 125,conduit 123 andvacuum adaptor 121 to a standard medical vacuum source (not shown). When the valve is in the first position as shown in FIG. 1, the suction of a vacuum source draws fluid or tissue through the cuttingcannula cavity 32 of theinstrument 12 intoconduit 129, throughpassageways 128, 164a, and 126a of thevalve 110, and throughconduits 132a, 125, and 123. Tissue or fluids drawn from the patient through this pathway are normally discarded without analysis.

When analysis of fluid or tissue samples is desired, therotor 150 can be rotated by an operator to break the fluid connection between thethird passageway 128 andfirst passageway 126a, and bring thethird passageway 128 into fluid communication with thesecond passageway 126b. Thesecond passageway 126b is connected in fluid communication with achamber 173 by aconduit 132b. Thechamber 173 is defined by acontainer wall 172 and holds tissue or fluid samples. Theconduit 132b connects to anipple 178 formed in acap 176 that is screwed onto the container 170. Since thechamber 173 of the container 170 is also in fluid connection with the vacuum source by way ofconduits 187, 127, 125, and 123, liquid or tissue samples are drawn by suction (inflow) into thechamber 173 of container 170.

Continued passage (outflow) of liquid or tissue samples throughconduits 187, 127, and 123 is inhibited by placement of filters that block or obstruct passage of the sample As illustrated by the broken-away portion of the container 170 in FIG. 1, afilter screen 182 is positioned in thechamber 173. Thefilter screen 182 is formed to define a plurality ofapertures 184 that permit withdrawal of air fromchamber 173 throughconduits 187, 127, 123, but prevent passage (outflow) of tissue samples sized larger than theapertures 184. A secondary, in-line filter 190 is also connected betweenconduits 187 and 127 to reduce passage of samples intoconduit 127 and trap small bits of tissue or fluid.

In operation, a surgeon or other medical personnel simply rotates therotor 150 from its first position with tissue passing directly to the vacuum source, to its second position, so that tissue samples are trapped in the container 170. The tissue sample containing container 170 can be disconnected (by unscrewing the cap 176) from thesystem 100 and taken for laboratory analysis. The remaining, now contaminated, elements of thesystem 100 are then disposed of by approved medical waste disposal procedures.

Operation of thetissue retrieval assembly 10 involves removal of thedisposable instrument 12 and tissuesample trap system 100 from a sealed and sterile package (not shown). Thesystem 100 is connected to vacuumsource 105 with thevacuum adaptor 121. Initially therotor 150 of the dual valve is turned to allow direct passage of tissue samples from thedisposable instrument 12 to the vacuum source, or alternatively the rotor is turned to block any fluid passage between eitherpassages 126a and 126b andthird passageway 128.

The surgeon inserts the disposable instrument into a patient's abdomen, with thebasket 50 fully folded as seen in FIG. 2. As best seen in FIG. 3, theshield tube 40 is retracted, allowing the prestressedflexible strips 52 to assume their arcuate shape and collectively define thebasket cavity 51. The surgeon maneuvers thebasket 50 to capturetissue 15, and then proceeds to move theshield tube 40 forward to reduce the volume of thebasket cavity 51 and closely hold thetissue 15 in place as best seen in FIG. 4.

The surgeon then operates thelever arm 22 to move the cuttingcannula 30 forward into thebasket cavity 51 to impact theanvil 60. This action cuts atissue core 19, as seen in FIG. 5. Upon separation from thetissue 15, thetissue core 19 is drawn through the cuttingcannula cavity 32 and either directly passes to thevacuum source 105, or more typically, is captured by the container 170 of the tissuesample trap system 100. As thetissue 15 is reduced in size, theshield 40 is moved forward, as shown in FIG. 6, to keep thetissue 15 tightly held. The process of moving theshield 40 forward, followed by cutting action with the cuttingcannula 30, is repeated until thetissue 15 is removed from thebasket cavity 51. Theinstrument 12 is then removed from the patient's body cavity and disposed of as medical waste. Tissue samples retrieved and held by thesystem 100 are stored or removed for analysis.

Claims (20)

I claim:

1. An instrument for dissecting and removing tissue from a patient's body, the instrument comprising

a collapsible basket formed to define a basket cavity to contain tissue, the collapsible basket being positionable in a patient's body to entrap said tissue,

means attached to the collapsible basket for collapsing the collapsible basket to allow insertion of the collapsible basket into a patient's body,

a cannula having means for cutting tissue at its distal end, the cutting means being movable to pass through the means for collapsing the basket to a distal end of the collapsible basket and to cut any tissue contained in the basket cavity,

means attached to the cutting means for moving the cutting means to cut tissue, and

means connected to the basket cavity for withdrawing cut tissue from the basket cavity.

2. The instrument of claim 1, wherein the collapsible basket further comprises a plurality of flexible members, each flexible member having a first and a second end, and each flexible member being prestressed to define an arcuate shape between its first and second ends.

3. The instrument of claim 2, wherein the second end of each flexible member is attached to an anvil and further comprising a support tube positioned to surround the cutting means, with the first end of each flexible member being attached to the support tube.

4. The instrument of claim 3, wherein the collapsing means further comprises a shield tube positioned to surround the support tube, and means for alternately moving the shield tube to straighten and effectively collapse said flexible members forming the basket and to withdraw the shield tube from contact with the flexible members to allow recovery of their arcuate shape and formation of the basket cavity.

5. The instrument of claim 1, wherein an anvil is attached to the collapsible basket to form an impacting surface for the cutting means.

6. The instrument of claim 5, wherein the anvil defines a tubular cavity dimensioned to conformably accept the cutting means.

7. The instrument of claim 6, wherein a solid plug is inserted into the tubular cavity to provide a solid impact surface for the cutting means.

8. The instrument of claim 5, wherein the moving means further comprises a support tube attached to hold the collapsible basket, a handle attached to the support tube, a lever arm attached to the cutting means, and means for biasingly connecting the lever arm to the handle so that operational movement of the lever arm relative to the handle moves the cutting means toward the anvil.

9. The instrument of claim 8, wherein the biased connecting means includes a hinge attaching the lever arm to the handle and a spring biased to urge separation of the lever arm from the handle.

10. The instrument of claim 1, wherein the withdrawing means further comprises means for providing a fluid connection between the basket cavity and a vacuum source.

11. An instrument for dissecting and removing tissue, the instrument comprising

a support tube formed to define a support tube cavity therethrough, the support tube having a working end insertible into a patient's body,

a shield tube concentrically positioned to surround the support tube,

a basket defining a basket cavity for holding tissue, the basket being formed from a plurality of flexible strips, each flexible strip having first and second ends, and with the first end of each flexible strip attached to the working end of the support tube,

an anvil attached to the second end of each of the plurality of flexible strips to further define the basket cavity,

a cutting cannula means reciprocatingly movable in the support tube cavity, the cutting cannula being extendable from the working end of the support tube to pass through the basket cavity and impact the anvil, cutting any tissue contained in the basket cavity,

means for reciprocatingly moving the cutting cannula means, and

means for moving the shield tube relative to the support tube to alternately collapse and allow expansion of the basket.

12. The instrument of claim 11, wherein the reciprocating moving means further comprises a handle attached to the support tube, a lever arm attached to the cutting cannula means, and means for biasingly connecting the lever arm to the handle so that operational movement of the lever arm relative to the handle moves the cutting cannula means toward the anvil.

13. The instrument of claim 12, wherein the biased connecting means includes a hinge attaching the lever arm to the handle and a spring biased to urge separation of the lever arm from the handle.

14. The instrument of claim 11, wherein the instrument also comprises a withdrawing means for providing a fluid connection between the collapsible basket cavity and a vacuum source for removing tissue contained in the basket cavity.

15. The instrument of claim 11, wherein the support tube is formed to define external threads, and further comprising means for engaging the external threads of the support tube, the engaging means being attached to the shield tube.

16. A method for dissecting and removing tissue from a patient's body, the method comprising the steps of

entrapping tissue in a collapsible basket formed to define a basket cavity,

providing an anvil attached to the basket,

cutting tissue trapped in the basket cavity by movement of a cutter, wherein the cutter moves to pass through the basket cavity and impacts the anvil, cutting any tissue contained in the basket cavity, and

withdrawing cut tissue contained in the basket cavity.

17. A tissue sample trap system, the system comprising

a collapsible basket formed to define a basket cavity to contain tissue, said collapsible basket having an anvil at an end thereof,

means for collapsing the basket to allow insertion of the collapsible basket into a patient's body,

a cutter means formed to define a cutting cavity, the cutter being movable to pass through the means for collapsing the basket and impact the anvil, cutting any tissue contained in the basket cavity,

means for moving the cutter to cut tissue, and

a valve body shaped to be gripped and securely held while leaving a thumb free for valve operational movement, said body providing first and second passageways alternately in fluid communication with a third passageway positioned in fluid communication with the cutting cavity, said valve body also formed to define a cylindrical opening extending transversely therethrough and in fluid communication with said passageways, a cylindrical rotor for snug slidable and rotational insertion into said cylindrical opening, the rotor having two transaxial passageways therethrough to provide alternate fluid communication between the first passageway and the third passageway, and the second passageway and the third passageway, and thumb-actuated means for rotating said rotor,

an airtight container formed to define a chamber for holding tissue samples,

inflow means for connecting one of the first or second passageways of the valve body to the container in airtight fluid communication, and

outflow conduit means for connecting the container in fluid communication to a vacuum source to withdraw tissue samples from the basket cavity through the cutter cavity, the third passageway, one of the transaxial passageways, one of the first or second passageways to said air tight container.

18. The system of claim 17, wherein the first passageway is connected to the vacuum source and the second passageway is connected to the inflow means.

19. The system of claim 17, wherein the outflow conduit means further comprises filtering means to prevent passage of tissue samples from the container through the outflow conduit means.

20. The system of claim 19, wherein the filtering means comprises a filter screen positioned in the chamber of the container, the filter screen being in fluid communication with the outflow conduit means, and having a plurality of apertures therethrough to allow passage of air and reduce admittance of tissue into the outflow conduit means.

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